A detector of the kind described above is disclosed in U.S. patent application Ser. No. 208,678, now abandoned, having the title "Method for Detecting Gaseous Materials by Means of an Enzymatic Redox Reaction and Apparatus therefor" filed on Jun. 20, 1988 and incorporated herein by reference.
This detector includes a porous filler disposed in a tubular vessel open at both ends. The filler comprises a carrier material on which the enzyme is applied for example by means of freeze drying or the carrier material can first be completely uncharged. The detector is closed in its operational ready condition. To prepare for measurement, the detector is opened and the carrier material is impregnated with a reagent solution. If the carrier material already contains the enzyme, then the reagent solution comprises, for example, an electron acceptor/donator complex and a chromogen which makes possible a color reaction required for the detection or, for the case wherein the carrier material is completely uncharged, the reagent solution at the same time contains the enzyme necessary for the detection. In both cases, the reagent solution must be separately prepared for each measurement so that the reagent solution can be directly applied to the filler in advance of the air sample determination.
It is also possible to separately store a completely prepared reagent solution; however, the handling and most importantly, the preparation of the necessary supplies is complex. The preparation to determine the gas specimen requires experienced manual operations by the user which must be carried out without error for a successful determination. Furthermore, the user must initially be able to estimate which quantities of components are to be provided in the reagent solution so that the anticipated quantity of the gas components to be determined can be completely converted. Since this cannot always be determined in advance, control or limiting measurements are necessary in accordance with measurement results.